This invention relates to flotation processes for recovering minerals from their ores. In another aspect of the invention it relates to the recovery of copper-bearing mineral sulfides from their ores. In another aspect of the invention it relates to the use of flotation agents and flotation depressants in the recovery of minerals from their ores.
Froth flotation is a process for concentrating minerals from ores. In a froth flotation process, the ore is crushed and wet ground to obtain a pulp. Additives such as mineral flotation or collecting agents and frothing agents are added to the pulp to assist in subsequent flotation steps in separating valuable minerals from the undesired, or gangue, portions of the ore. The pulp is then aerated to produce a froth at the surface. The minerals which adhere to the bubbles or froth are skimmed or otherwise removed and the mineral-bearing froth is collected and further processed to obtain the desired minerals. Frequently, other chemicals are added to the separated mineral-bearing froth to assist in subsequent separations particularly when significant proportions of two or more minerals are present in the separated mineral-bearing froth. Such chemicals are known as depressant agents. These materials are sometimes referred to more appropriately as deactivators and are used selectively to separate one type of mineral from another type of mineral. In sulfide mineral flotation, a depressant action is achieved on copper sulfide by the use of sodium sulfide. U.S. Pat. No. 3,785,488 discloses the use of thio alcohols as depressant agents in a froth flotation process for recoverying molybdenite (MoS.sub.2) from a metallurgical concentrate in which there is a major portion of copper sulfide and other sulfides and a minor portion of molybdenum sulfide. The essence of the instant invention is to provide an alternative family of copper depressants for ore flotation processes.
It is therefore an object of this invention to provide compounds suitable as depressants for copper-bearing mineral sulfides for use in ore flotation processes. It is another object of this invention to provide a method for recovering copper-bearing mineral sulfides from their ores using ore flotation processes. It is still another object of this invention to provide ore processes employing both flotation agents and flotation depressants.
Other aspects, objects and the various advantages of this invention will become apparent upon reading this specification and the appended claims.